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.B. H. THWAITE; HIGH SIEMPBRATURBPURHAGE FOR STEEL MELTING 0R ANALOGOUS PURPOSES.

N0. 515,452. Patented Feb. 27, 1894-.

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(No 140691.? A Sheath-Sheet 2 HIGH TBMPBRATURBPUR 10B] FOR; sum; *MBLTING OR-ANALOGOUS PURPOSES.

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B.H. THWAITE. HIGH TEMPERATURE FURNACE FOR STEEL MELTING 0R ANALOGOUS PURPOSES.

No. 515,452. Patentgd Feb. 2'7, 1894.

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VINO Model.) 4 Sheets-Sheet 4. B. H. THWAITB. HIGH TEMPERATURE FURNAGE FOR STEEL MBLTING OR ANALOGOUS PURPOSES. 5N0. 515,452. Patented P55. 27, 1594.

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UNITED STATES PATENT OFFICE.

BENJAMIN H. THWAITE, OF LONDON, ENGLAND.

HIGH-TEMPERATURE FURNACE FOR SIEEL-MELTING R ANALOGOUS PURPOSES- SPECIFICATION forming part of Letters Patent No. 515,452, dated February 27, 1894. Application filed July 8, 1893. Serial No. 479,924. (No model.) Patented in England January 22, 1 11 h 1 To all whom it may concern:

the air to support combustion.

This invention has for its object the improvement in furnaces intended for using either gaseous or solid fuel, but especially for the former fuel-and where temperaturesof combustion equivalent to the degree required for the fusion of steel of low carbon quality is desired.

In my furnace I use air recuperators. Around a'whole or part of such recuperators (external sides), I provide an air jacket through which by plenum or aspiration I pass These air recuperator chambers debouch directly into the air and gas mixing chamber, the area of the passage serving as connection, having rather less than the area of the inlet flue; this permits an equal pressure of air to be established throughout the chamber. I connect the two air recuperator chambers when placed above the furnace at the upper ends, by means of a central reversal valve, through the aid of which the air isalternately directed into the chimney for the purpose of steam raising, according to the system adopted for puddling furnaces, or I mayforcethe residual gases from combustion through a head of water so as to abstract the necessary sensible heat, or I may employ, in order to facilitate the removal of the gases-ah exhaust fan or steam jet aspi- For the central valve I use.

rator. In order to reduce the thermic radiation from the roof of furnace, I may suspend just over this roof a sheet iron plated vessel which I may connect up to the pipe through and by which the heat radiated from the furnace is transferred to the air, such sheet iron and castings may be of the lightest of iron scantlings.

Before referring in detail to the four sheets of drawings that accompany and are intended to form part of this specification, I wish it to be confined to the exact details shown on such illustrations, as they may be modified very considerably without involving any departure or enlargement of the rights covered by my claimsas hereinafter set forth.

I will describe each set of illnstrationsshowing a specific application of my inventionseparately and with distinctive symbols of referenceinstance the application shown on Sheets 1 and 2 of drawings.

Figure 1, in Sheet 1 is a front elevation of the furnace, and Fig. 2, is a plan in section, taken on lines a b of Fig. 1. Sheet 2 of drawings is a vertical section of furnace taken on line 0, d of Fig. 2 of Sheet 1 of drawings,while Fig. 4, is a sectional plan on line e, f of Fig. 3. Fig. 5, is a vertical section of a modified form of furnace and Fig. 6, a sectional plan view of the same. Fig. 7, is a side view showing the means for operating the valves.

The following are the essential structural elements of the furnace.

The hearth itself in which the conversion is proceeded with, is marked A, the ports by which the fuel gas enters the furnace are marked B, the chambers in which the gas is mixed with the air are marked 0. The two recuperators in which the air is heated by the flow of the products of combustion are marked D. The pipes and tubes leading the air from blower to the air recuperator jackets are marked E. The air jackets surrounding the air recuperators are marked F, said jackets having horizontal partitions F. The air reversal valve is marked G, the two gas valves are marked H.

We will follow the cycle of combustion and the sequence of recuperation-the air enters the furnace by means of the inlet E, flowing be clearly understood that I do not intend to Fig. 3, on

into the sheet iron formed chamber L,-sus

finally flows into the air reversal valve G,

and from thence into the interior of one or other of the recuperators D, which are filled with checker brick-work, this brick-work heated to a high temperature, transfers its heat to the air, flowing through the brickwork and before it reaches the locale of mixture of the air and gas-or the mixing chamber M-+=the air attains-a very high temperature which adds to the temperature resulting from the combustion per se.

The gas and air mixing chamberlVI, may,or may not be filled, with checker brick-workthe general construction of this chamber is shown in Fig. 2, in which figure two alternative arrangements of mixing. chamber are shown-one V M being shown filled with checker Work and the other M being merely an empty chamber having contracted ports leading to hearth of furnace N. v

The air being preferablyforcedinto recuperator chambers by means of aRoots blower, fills every part of: the recuperator and] is in sensible contact with every brick contained. Itisobvious that the gas supply mustestab lish-a pressure equal to that. of thezair-and I- arrange-thatsu-ch a pressure of gas. supply is provided. Thefuelgasentersin to the mixing V or combustion chamber M, enteringby thevertical gas fines Owhichareclosely connected to gas valves H. a The gas entering. into-the mixing. chamber M is thoroughly intermixed with the heated air -which having along with the chamber a very high temperatureraises the in-;

tensity of combustion: to a degreeonl'ylimited by the limit of inf-usi bility of the bricks that structurallyconstitutethefurnacer The flame fiowsacross the hearth, impinging on every part because the pressure ot the gasesof com bustion is such as to balance the in rush of cold air intothe, furnace through thedoors. The heated gases, fill the mixing chamber Matt'h'e opposite end of furnacecharging them with heat of a steel melting intensity.thegaseous products of combustion flowing through the recuperators D, charge their checker 1 brick-work with heatto nearly the same extent, but the temperatureof course beingless in the upper than the lower partot the cham'be'rsthe sensible temperature of the gases escaping. into the reversal valve G,- whic'hissof the usual butterfly type-being very low. I y

The; gas valves H are of the mushroomvalve type (formed preferably of mild steel). -sit-" ting on steel plateshaving special seatings to enable a perfect joi-nt to be formed.

The rising gas uptakes or fluesO, I fornr of sheet iron internally lined with refractory material and so arranged as to be rapidly overhauled and renewed.

The chimney P, above the air reversal valve G, is of ordinary sheet steel or sheet ironbut I may surround it with a water space, for steam raising urposes, as shown t Q.

Fig. l, shows a plan in section through recuperator chambers D. 7

Referring to Sheet 3 of drawings, Fig. 5 shows a vertical section of another form of applying my invention-and Fig. 6 shows a plan in section of same.

In this applicationthere is the same disposition of essential parts as in the former arrangement just described. The principal difare s'u pported on a solid block of brickwork f containing in their. center the vertical gas flue O which debouches at the point B, into the locale where the air meets the gas whi-ch inthis application is a widenii-ng flne having across it a, series of walls of checkers S.-

to prevent prematureignitionacove'r arch T is provided by which the: gas is directed on to the checkers I In other essential detailsthe arrangement is similar to the design already described, and the same letters of reference refer to identicalparts. The air pipesU, lead the air to the jackets surrounding the recuperators, the air in. passing through the jackets 1 abstracts the, heat radiated therefrom and J before enterin g the air reversal valve G is very highly heated. V p

I may decide. to automatically reverse the Q valves G and H, so as: to insure absolute regularity of reversal action. automatic water tilting gear shown in Fig. 7. which also showsone arrangementby an elevation of a furnace built accord-ing to my id!- ven-tionand. which I; adopt for incasing. the furnace withiron plates, tomaintainthe integrity of structural fermof the furnace; the I essential elements are indicated by the same reference letters indicating the same parts. The simple action of tilting serves to throw g over theweighted lever which aetuates the balancedand weighted. levers 01: the upper t air reversal valve G. llhese centralweighted levers are connected by links to. a central lower balanced lever f, that by othencennectionsof chains 0, to .the gas valves H lowers and closes one valve and raises and opens another. V V is d marks the balanced lever and attached 1 balance-weight e at each end of the-lever a [there is a-bucket g, assoon as the bucket is filled with water flowing from thervalvelcthe .wei'ght of thewater tilts the bucket, thus L pulling the weightedlever al over thecenter line, the bucket and balance weight. fall to their full extentthe tilting action throwing out the water which by the reversal of the valve 70, is diverted into the. opposite bucket I such reversal of valve lobeingeffiectedby the Q links j that actuate the cross. lever Z0" by regulating the flow of thewater, the time of reversal can be precisely determined. It will i be obvious that this arrangement can be worked by hand without any modification of ference is a structural one. The recuperators I e t a imp 1 In order to" divert the gas on to the air and IIC the gear being required. In order to obviate any difficulty from the presence of the supporting column c, the latter is placed some distance away from the furnace, the actuation of the valves being efiected by the extension of a shaft m forming the center of the tilting lever, and the repetition of another tilting 1ever at the end of such shaft, the shaft being connected to the three reversal valve levers.

Of course there are other automatic reversal gears that I may decide to use in preference to the one described.

I claim 1. In combination with the furnace, the air and gas supply conduits, the mixing chambers at the ends of the furnace, the air recuperators, the air jackets about them, the reversing valve G with its casing and the connection from said valve casing to the air re cuperators and to the air jackets about the same, substantially as described.

2. In combiuation,the furnace, the gas supply conduits, the air supply pipe the mixing chambers and the air heating chamber of sheet metal connected with the air inlet pipe and suspended at the lower end thereof over the roof of the furnace, substantially as described.

3. In combination, the furnace, the gas supply conduit, the air supply, the mixing chambers, located at the ends of the furnace and to which the gas supply conduit leads the recuperators, connecting with the mixing chambers the air jackets extending about the re- Witnesses E. A. WEST, J. W. VIoKERs. 

